Saving lives and limbs

Research by UC Davis neuroscientist Ebenezer Yamoah may one day lead to a biological implant that restores hearing and, unlike today's cochlear implants, preserves the structure and function of sensory cells and nerves of the inner ear.

Yamoah, a professor of otolaryngolgy, has discovered adult stem cells in mice that may resemble inner-ear sensory cells. These cells are responsible for receiving vibrations of the fluid in the inner ear and sending signals to the brain, which are interpreted as hearing. Yamoah and postdoctoral researcher Dongguang Wei have begun to search embryonic stem cells that are the progenitors of these inner-ear sensory cells.

Those who spy Dick Martinez on a golf course or racquetball court wouldn't guess the 68-year-old lost every toe on his right foot due to complications from diabetes. The Colorado native firmly believes in the promise of stem cell therapies. At his age, however, it's not so much for himself as for his wife's 9-year-old granddaughter, who also suffers from diabetes.

Martinez hopes that diabetics may one day benefit from stem cell therapies under way at UC Davis Health System.

"Try walking a mile in the shoes of a diabetic. It's a terrible disease," he said. "We need to support research to cure it."

California's stem cell agency will fund $3 billion in research over the next decade for stem cell therapies for a host of diseases, including diabetes.

At UC Davis, a primary focus of research is on peripheral artery disease, a common complication of diabetes that results in poor leg circulation. Surgery is the only remedy for this condition, which can lead, in its most advanced stages, to amputation and even death.

But stem cell therapies being developed at UC Davis by Jan Nolta offer hope for regenerating damaged blood vessels.

"Our lab used adult human stem cells to successfully treat mice with hind-limb ischemia — damage due to low blood flow and oxygen," said Nolta, director of the UC Davis Stem Cell Program. "We are now seeking approval from the U.S. Food and Drug Administration to make these promising results available to patients with severe peripheral artery disease."

Nolta, whose father suffers from peripheral artery disease, calls adult stem cells the "paramedics of the body." Found in bone marrow, these cells search out damaged tissue and repair it.

"We need new ways to treat peripheral vascular disease so we can prevent limb loss," said Laird. "We have limited treatment options for patients with severe disease, and no medications to help relieve symptoms or to improve quality of life. Stem cell therapies are especially important for these patients and those who are not candidates for angioplasty, stenting or other surgical repair methods."

It's an effort that Dick Martinez will be following closely. After all, he wants his granddaughter to have a much healthier life when she grows up.